Ellipsograph



(No Model.) 2 Sheets-Sheet 1.

J. HARWOOD.

ELLIPSOGRAPH.

Patented July $2 1884.

, i w y if. PErERs. Pmtwlilhnmphw. Wnhingtm O. a

(No Model.). 2 Sheets-Sheet 2.

J. HARWOOD.

. ELLIPSOGBAIPH.

NQ. 302,247. Patented July 22, 1884.

I INVEN Lu W I I I 25 pencil-holder.

Tarts rrn JOHN HARVOOD, OF OSHKOSH, \VISCONSIN.

ELLIPSOGRAPH.

EPECIFICATION forming part of Letters Patent No. 302,2 dated July 22,1884.

Application filed April 1, 1884. (No model.)

To all whom it may concern.-

Be it known that I, JOHN HARWOOD, a citizen of the United States,residing at Oshkosh, in the county of NVinnebago and State of\Visconsin, have invented certain new and useful ImprovementsinEllipsographs; and I do declare the following to be a full, clear, andeX- ,aot description of the invention, such as will enable othersskilled in the art to which it apio pertains to make and use the same,reference being had to the accompanying drawings, and

to the letters and figures of reference marked thereon, which form apart of this specification.

My invention relates to devices for describ ing ellipses, circles,parallel lines, 820.; and it consists in the construction, combination,and arrangement of several parts, as will be hereinafter described andclaimed.

In the drawings, Figure l is a plan view of my invention. Fig. 2 is adetail View of my T-frame. Fig. 3 is a detail of the sliding plate. Fig.4 is a detail view of the sliding center. Fig. 5 is adetail view of theswiveled Fig. 6 is a detail view of the pencilcarrier. Fig. 7 is adetail of-the pivotolock. Fig. 8 shows the disk and graduated plate.Figs. 9 and 10 are detail views of the edge guide or support. Fig. 11 isa detail of the swiveled pencil and its supports. Fig. 12

is a plan view of the device with the trams extended. Fig. 13 is asection on line z 2, Fig.

1. Fig. 14 is a detailed side view of the extension.

The T-bar A, forming the main or supporting frame, is composed of thearms A A, the latter being secured midway its ends on one end of arm A,and at right angles thereto. A short bar, A projects from the outer sideof the arm A and in line with the arm A. This short arm is provided atits outer end with a point or indicator, a. A clampingscrew, a, turnsthrough the shaft-armA and binds against-the base plate presentlydescribed. The arms A A have longitudinal mortises formed in their upperfaces, which mortises intersect, as clearly shown in Fig. 2. An opening,c formed through the center of arm A serves to permit passage of thescrew '0 or bolt that serves as a pivot for the T-bar. This T-bar. maybe pivoted by a screw or pin direct-1y on the card-board or sheet onwhich it is desired to make the lines; or it maybe pivotally secured ona plate, B, as shown. This plate is preferably made in the form of aquadrant, and is provided in its upper face with a series ofindentations, b, to receive the point of screw a, when the bar A hasbeen adjusted to the desired position. A segmental plate, B, has itsinner edge fitted to the outer or curved edge of plate B, and isprovided with a series of graduating lines, 11, radial to the pivot ofthe'T-bar, and in position to register with the pointer a, so that thebar Amay be set at any desired angle,and brought back again to any givenpoint when moved therefrom, as will be presently described. The plate Bis secured to quadrant B, preferably by means of ears b projected fromthe quadrant into slots 1) in theplate B, as most clearly shown in Fig.8. Tram-bars O D are placed in the mortises of the arms of bar A, andare secured in place by screws E, turned through the sides of the barand binding against the tram-bars. These trams are provided in theirupper sides with dovetail grooves, in which slide the traveling blocks.The tram D is so arranged that the base of its groove comes flush withthe top of tram C, so that the block sliding on tramD may be drawn overtram O,when it is desired to strike a circle from the pivot of theT-bar, as will be presently described. Block F slides on tram O, andblock G on tram D. For convenience of reference, I will denominate theformer the traveling guide-block, and the latter the traveling pivotblock. These blocks are provided on their under side with dovetail ribsfitted to the grooves in the trams. The pivot-block is composed of upperplate, 9, and lower or dovetail plate, 9, which latter has pins gprojected from its opposite ends up through the upper plate. The pin 9serves as a pivot for the pencil-bar, and the pin g is threaded on itsupper end to receive nut G, which,when turned tightly down on said pin,draws the plate 9 against the walls of dovetail slot in the trams, andsecures the block immovably thereto, as will be understood.

The block F is provided with an upwardlyextended stud, F, which entersthe block on the pencil-bar H. This pencil-bar has its inner end pivotedon the inner end of block G, and is provided with block I, andapencilholder, J. The block I is slotted and slipped over the penoil-bar. It has a clamping-screw. 1, whereby it may be secured at anydesired point along the bar H, and a socket, 1 in its under side toiiton stud F of the guide-block. The pencil-holder J is perforated andslipped on the pencil-bar, and has a set-screw, J, which enables thesecuring of the holder to the bar in any desired position. This holderalso has a socket, J for the pencil, and a setscrew, J", for retainingthe pencil therein. It will be noticed that plates K are interposedbetween the points of screws 1 and J and the pencil-bar, to receive thebearing of said screws and prevent damage to the pencilbar.

A short bar, M, is fitted to be inserted in the end of the trams, and issecured thereto when desired, as shown in Fig. 11, and indicated inFig. 1. A pencil-holder, M, has a lateral wing, 1W, which is pivoted byscrew M on the outer end of the bar M, so that said holder may be swungfrom side to side to any desired point, and held thereat by tighteningits pivot-bolt. By loosening the screws E the tram may be moved back andforth in the slot of its supporting-arm, so as to drawlines parallel toeach other and to the line of motion of the tram.

It will be understood that when one line is drawn the screw M isloosened, the holder M swung to its desired position, as indicated inFig. 11, and then securely clamped by said screw M and another linedrawn. By turning the T-bar on its pivot, lines may be drawn parallel toany given radii of said bar.

In operation, when the parts are as shown in Fig. 1, it will be seen byswinging the pencil-bar from side to side one half an ellipse will bedescribed by the pencil. The screw a is then loosened and the frameturned halfway around, and the remaining half of the ellipse will bedescribed, as before. If it be desired to increase the transversediameter of the ellipse,the screw I should be loosened and theguide-block slipped back in the pencilbar, and secured at a point nearerthe pivotblock. To decrease the transverse diameter the guide-blockshould be moved to and se cured nearer the pencil-block, as will be appreciated.

By adjusting the pencilblock and guideblock on the pencil-bar, and thepoint of pivoting the bar on the pivot-block the longitudinal axis ofthe ellipse may be varied, as desired. The pencil-bar is usuallysupplied with a-scrics of holes, H, near its inner end, so that itspoint of pivot maybe varied as desired. Now, by removing block I fromthe guide-b1ock, and moving the pivot-block in its slot up, so thatpivot of pencil-bar will coincide with that of the main frame, andsecuring it at such point by nut G, or in other suitable manner, thepencil-bar is so arranged as to strike by revolving it on its pivot. InFig. 12, I have shown the manner of using my eX- tension guide andsupporting frames, the detail construction of which parts is shown inFigs. 9 and 10.

The guide extension-frames N are provided with ears N, or other suitablemeans whereby they may be attached to the board, and longitudinalmortises N in their upper sides, corresponding to the mortises in bar A.Screws N are also provided whereby to clamp the trams in said frames N.These frames, it will be seen, are arranged in line with one of the armsof the main frame, so as to support the trams when it is desired to formlarger ellipses than can be described by means of the devices beforedescribed. The uses and operation of these extension-supports N areclearly shown in Fig. 12. The tram may be arranged as shown in fulllines, said figure, and one quarter the ellipse struck. It is thenadjust ed to the position indicated in dotted lines,

In this plate or flange, 0, which, in operation, are

screwed or otherwise secured to the edge of the board or table, as willbe understood from Fig. 12. This frame is adapted to support the T-frameA, which is secured thereto by means of a screw, 0 or in other suitablemanner desired. By this means the said frame may be supported beyond theedge of the board or table to enable the forming of elliptical curvesnear said edge, or for any other desired purpose.

It is manifest that many modifications might be made in the form of thedetail of my device without departing from the broad principles of myinvention.

Having thus described my invention, what I claim, and desire to secureby Letters Patent, 1s-

1. An ellipsograph comprising a support ing-frame having right-angledarms, bars, or trams removably and adjustably secured to the arms ofsaid frame, and adapted to support the traveling blocks and the guideand pivot blocks supported on the bars or trams and the pencil-bar,substantially as set forth.

2. The herein-described ellipsograph, consisting of the base-plateprovided with indentations, the graduated plate, the' pivot-suppOliJlDQ,frame having grooved arms, and an extension, A registering with thegraduated plate, the clamping-screw whereby the frame may be secured atany desired point, the trams secured in the arms of thesupporting-frame, the pivot and guide block, and the pencil-bar, allsubstantially as and for the purposes set forth.

3. The combination of the trams C D, suitably supported and provided ontheir upper faces with grooves, the groove of tram D being formed withits base flush with the intersecting surface of tram G, the travelingpivot-block operating on tram D and movable over tram (J, pencil-barpivoted to the pivotblock, and means for securing said block at anydesired point, substantially as set forth.

4. The combination, with a suitable guidesupport, of a bar movablelongitudinally therein and a pencil-carrier secured to the outer end ofthe bar and capable of adjustment from side to side in a plane with itssupporting-bar, whereby lines may be drawn parallel to said bar and toeach other and any suitable desired distance apart, substantially as setforth.

5. The combination of the supporting-frame having an arm, A the trams,the traveling blocks, the pencil-bar, the quadrant having a series ofindentations, and a screw turning through the supporting-frame andengaging said indentations, substantially as set forth.

6. The combination of the quadrant provided with indentations, thesegmental graduated plate, the pivoted supporting-frame provided "with ascrew arranged to engage the indentations in the quadrant, and a pointeradapted to register with the graduations on the segmental plate, thetrams, the traveling pivot and guide blocks, and the pencil-bar,substantially as set forth.

7. The combination, with the double-armed supporting-frame havinggrooved arms, and the trams, traveling blocks, and pencil-bar, of theguide extension-frame adapted to support the trams and to be secured inline with the arms of the supporting-frame, substantially as set forth.

8. The combination of the double-armed supporting-frame, the trams, thetraveling blocks, the pencil-bar, the guide-extensions, and the edgeextension-frame, substantially as set forth.

In testimony whereof I affix my signature in presence of two witnesses.

J OHN HARXVOOD.

- \Vitnesses:

GEO. F. WRIGHT, A. E. BIRNBAUM.

